package two;

import java.util.Scanner;

public class test10343 {
    private static int[] array = new int[21];
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        if(n==2){
            System.out.println("No answer");
            return;
        }
        System.out.println(getNum(n));
    }


    private static int getNum(int n) {
        int sum=0;
        if(array[n]!=0){
            return array[n];
        }
        if(n==2||n==3){
            return 1;
        }
        if(n>=4) {
            for (int i = 2; i < n ; i++) {
                sum += getNum(i) * getNum(n + 1-i);
            }
        }
        array[n]=sum;
        return sum;
    }
}
